JAMS is available in two flavors:
- as a Windows installer that allows easy setup on Windows systems, and
- as a platform-independent zip-archive which can be used to run JAMS on any platform that supports Java.
For information on how to install JAMS, please have a look here.
Both versions contain the same functions and components, which include:
- JAMS runtime system with the core components needed to run JAMS models
- modelling libraries which contain more than 200 components that
- allow to simulate a wide range of hydrological and environmental processes, and
- provide functions for data analysis, data I/O and graphical visualization
- graphical user interfaces for
- building, configuring and running JAMS models (JAMS Launcher and JAMS Builder)
- analyzing and visualizing model input and output data (JAMS Data Explorer) including 3D map visualization using NASA World Wind
- a toolbox for model parameter optimization, sensitivity and uncertainty analysis (OPTAS) that can be used to calibrate and analyze any JAMS model
- an automated documentation generator based on DocBook and XSLT transformation and Apache FOP (currently Windows only)
In addition, JAMS comes with two test models that demonstrate a number of JAMS functions and that can serve as a blueprint to setup your own models. These models are:
- the USGS Thornthwaite model, a simple lumped water-balance model working on a monthly time step 
- the fully distributed hydrological process model J2K 
Both models are located in the "data" subdirectory of the JAMS installation. To run the model, follow these steps:
- Start the JAMS Builder and choose "File"->"Load Model..." from the main menu
- Navigate to the "data/j2k_gehlberg" ("data/thornthwaite") folder and choose the "j2k_gehlberg.jam" ("thornthwaite.jam") file to be opened
- Choose "Model"->"Run Model" from the main menu (or press the button from the toolbar) to start the simulation
 McCabe, G. J. & Markstrom, S. L. (2007). A Monthly Water-Balance Model Driven By a Graphical User Interface (Open-File Report No. 2007–1088). U.S. Geological Survey.
 Krause, P. (2002). Quantifying the impact of land use changes on the water balance of large catchments using the J2000 model. Physics and Chemistry of the Earth, Parts A/B/C 27(9–10), 663–673. doi:10.1016/S1474-7065(02)00051-7